Private information for more than 18,000 private accounts of Morgan Keegan were publicly breached due to mishandling by the state securities commission, a release from the company said.

Morgan Keegan said a highly confidential document containing sensitive information about clients fell into the hands of a plaintiff’s lawyer in a pending customer arbitration.

The Memphis-based financial advisory firm said the information had been disclosed to the Alabama Securities Commission via inquires about RMK Bond Funds.

“When we provided the document, we did so in reliance upon state law that prohibits unauthorized disclosure and use of this information, and only after we obtained assurances that this information would be treated as confidential,” a release said. “The information contained in the document includes a range of account and personal information on approximately 18,500 accounts.”

The attorney who obtained the document is Andrew Campbell, who is also a member of the Alabama Securities Commission, the release said. According to the release from Morgan Keegan, Campbell produced it in private arbitrations filed by his law firm – Leitman, Siegal, Payne & Campbell, P.C. – against Morgan Keegan.

Campbell wasn't immediately available for comment, but representatives from his firm said Campbell did not personally view the information and said the information was returned to the Alabama Securities Commission earlier this year.

Morgan Keegan is a subsidiary of Birmingham-based Regions Financial Corp. (NYSE: RF). It is one of the largest brokerage firms operating in Nashville.

Clients whose information was publicly breached have been notified, and credit watch services have been given to all affected clients.